Configure QCMM Tax and Understand the Checkout Calculation

QCMM applies the configured tax rate during checkout calculation and stores the resulting tax amount with the commercial record. Changing the current tax setting later must not recalculate historical billing evidence.

Configure the Current Tax Rate

  1. Open QCMM Administrator Settings.
  2. Set the site tax rate used for new checkout calculations.
  3. Save and run a test checkout before accepting live transactions.

How Tax Fits the Checkout Calculation

QCMM calculates the current transaction from the applicable Plan price and eligible pricing adjustments, then records the tax and resulting totals in the checkout/billing snapshot. Review the order summary before payment so the subtotal, discounts, tax, Site Credit, and final balance match the intended transaction.

Historical Tax Is Preserved

The tax amount saved with an existing billing record is transaction evidence. A later administrator change to the current tax rate affects future calculations; it does not rewrite the tax previously charged on completed or historical records.

Verify a Change

  • Test a new checkout and confirm the expected tax amount.
  • Confirm the final billing record retains that amount.
  • Open an older billing record and verify its saved tax remains unchanged.

Community Discussion

Want to compare QCMM workflows or discuss how other Joomla site owners use this feature? Visit the QC Memberships & Meetings Community. For private support, account-specific entitlement or billing issues, or bug reports, use the QuantaCade support system.